Ibrahim al-Asghar al-Murtada ibn Musa al-Kazim

Ibrahim al-Asghar, also called al-Murtada in specialist genealogical literature, emerges as a son of Imam Musa al-Kazim distinct from Ibrahim al-Akbar. Bahr al-Ulum argues that early general biographies naming only one Ibrahim do not negate two persons and that the specialist genealogists' distinction carries greater weight.

Umdat al-Talib and related genealogical works treat him as the Ibrahim with an established continuing line. The strongest account carries his descendants through Musa Abu Subha and Jafar; some later works add a third branch, but the two principal lines are more consistently preserved. Numerous Musawi sayyid families trace through these branches.

The identification of the Yemen political figure is the largest dispute attached to his biography. Abu al-Hasan al-Umari and some later genealogical transmitters assign the Abu al-Saraya-era Yemen activity to the younger Ibrahim, while Ibn Inaba and Abu Nasr al-Bukhari call that figure Ibrahim al-Akbar. Early political chronicles record only Ibrahim ibn Musa ibn Jafar in the events of 200 and 202 AH, so the political role cannot be stated as certain for him.

The title al-Murtada is comparatively well established for his distinct genealogical identity, whereas al-Mujab appears mainly in much later family trees and devotional traditions. The mother's name also varies between forms such as Najiyya or Najiba and is assigned inconsistently to the elder or younger Ibrahim. Because the documented mother details are blank, no maternal identity has been asserted as settled.

Later sources variously place his death in Baghdad, burial at Maqabir Quraysh or al-Kazimiyya, and sometimes identify a Karbala grave or Ibrahim al-Mujab with him. These attributions conflict and lack decisive early support. His birth and death dates and cause of death are also insecure, so burial remains unknown and all local identifications are treated as attributed traditions.